Last couple of days I've been configuring a forest with two trees (domain1.local and domain2.local as the respective DNS names for the two root domains) in VMware in order to practice setting up trusts. I have currently got the two root domains in place with domain controllers working quite happily as DNS servers for each respective tree. I then created a child domain in the first tree called child1.domain1.local and this worked fine with the child domain folder added to the DNS zone for domain1.local. I then went to create a child domain in the second tree (child1.domain2.local) but this time the Active Directory install wizard stalled at the point where it shows "Examining an existing Active Directory Forest" or very similar and then displays the error message that it cannot connect to the PDC emulator which is the domain controller in the first tree. Now PDC Emulators are domain level operations masters so I'm confused about why the AD wizard is trying to connect to the PDC emulator in the other root domain when presumably the domain controller in the root domain of the second tree will also be functioning as a PDC emulator.